Here at Rotographs, it is brought up quite often that a player’s xBABIP and BABIP don’t agree. With the help of slash12, I have created a quick and easy method of calculating a hitter’s xBABIP. I have a downloadable spreadsheet that takes the batted ball data and calculates a xBABIP.

While others have created other xBABIP formulas, I find the one from slash12 (originally published at Beyond the Boxscore) to be the most accurate.

xBABIP = 0.392 + (LD% x 0.287709436) + ((GB% – (GB% * IFH%)) x -0.152 ) + ((FB% – (FB% x HR/FB%) – (FB% x IFFB%)) x -0.188) + ((IFFB% * FB%) x -0.835) + ((IFH% * GB%) x 0.500)

Here is a description of the formula’s creation and usage from slash12 in his own words:

This xBABIP formula was something I developed to provide an easy way to estimate a batters BABIP given his batted ball percentages as they appear on Fangraphs. I did this by doing a linear regression on the batted ball percentages against historic batted ball data. I’ve found that it has a very high correlation with a batters current year BABIP, however, sample sizes need to be considered as with everything else. Given the fickle nature of BABIP in general, it’s recommended you keep in mind a batters historic BABIP as well. A career .300 BABIP hitter isn’t likely to be a true .360 BABIP hitter, even if his batted ball data says that he is over the course of a partial season.

Here are a couple simple examples where this equation is useful:

Player X 2010: .300 xBABIP .290 BABIP
Player X 2011(April->June) .307 xBABIP .220 BABIP

Here, xBABIP helps reassure us, that Player X is most likely the same hitter he’s always been, he’s just been having some bad luck.

Player Y Career: .330 xBABIP .340 BABIP
Player Y 2010: .370 xBABIP .390 BABIP
Player Y 2011(April->June) .372 xBABIP .380 BABIP

Player Y may have indeed changed his approach in 2010, and 2011 in such a way that his hitting for higher BABIP is legit (perhaps he’s gained bat speed, or a previous injury has finally healed).

Finally, open the downloaded spreadsheet and Paste the copied data into the spreadsheet (select/highlight the Yellow box that designates the first year before pasting).That is it. The xBABIP values will be automatically generated.

A players xBABIP will be calculated without having to hand enter every number. Hopefully you find the information useful and let me know if you have any questions.

Jeff, one of the authors of the fantasy baseball guide,The Process, writes for RotoGraphs, The Hardball Times, Rotowire, Baseball America, and BaseballHQ. He has been nominated for two SABR Analytics Research Award for Contemporary Analysis and won it in 2013 in tandem with Bill Petti. He has won four FSWA Awards including on for his Mining the News series. He's won Tout Wars three times, LABR twice, and got his first NFBC Main Event win in 2021. Follow him on Twitter @jeffwzimmerman.